Final ME 170 Project

So we just finished our final project for ME 170. For this project, we had to make an assembly of parts, where at least one part moved relative to another. We were allowed to make something that already exists, but we had to make some modification or improvement to it. We chose to make a toy Transformer, which unfolded from a flashy sports car into a Transformer robot whose arms and legs detached to reveal markers inside. It was a pretty cool concept, and definitely went beyond what was expected. Since this project was so challenging, it took us well over 100 hours in the EWS labs to finish, including some really late nights and an all-nighter. It turned out well, however, so hopefully it was worth it. We do really feel that we have a good grasp of ProE Wildfire now.

To make our project, we used a similar approach to the Ark of the Covenant (see my earlier post for info on that). This was another "artistic" design, but instead of making one design, we had to make 2 that fit together in both positions! We decided to simplify things greatly by making the Transformer just open its doors and have the arms fold out, and the legs slide out of the rear of the car. This was a lot easier than the actual Transformer toys (though still quite challenging). The first thing we worked on was making the basic frame of the car. To that, we added doors, wheels, and a bottom. Then we had to make the hinges and parts of the actual Transformer, which is when we ran into trouble. We had made the sides of the car on an 85º angle, which meant the doors had to be on that angle as well. The hinges, however, had to be vertical, otherwise the doors would open at an upward angle, which would not work. While we could have just made the sides of the door vertical, we wanted to retain the visual appeal and realistic appearance of an actual car, so we stuck it out and after countless hours and many attempts, finally got the door to fit onto the car without any interference.

We dealt with many other problems on the way, but after it all came together we hit another roadblock: engineering drawings. These drawings show the dimensions of all the parts we made. That means the more complicated the part, the more convoluted the drawing, because it has more dimensions to show on the same 8 1/2 by 11 sheet of paper. Most of the parts weren't too bad, but when it came time to dimension the car body, with its many curves, extrusions, and holes, it took some clever organizing and about 4 pages of drawings to show everything we needed to show.

All in all, I think this was another successful project. We definitely set the bar high with our difficult design, but just like our last project, it really shows that we put as much effort into it as we did. Making markers that fit into a robot that can fold into a car is no small feat, especially when you have to stay up until 5 am every night for a week to get it done, but we're really proud of our work in this class!

Rube Goldberg Society

For the past few months, I have been participating in the Rube Goldberg Society. We are designing and building a Rube Goldberg machine to compete in nationals in March. For those who don't know, a Rube Goldberg machine is a complicated device that performs a simple task very inefficiently. This year, the task is to dispense hand sanitizer, and the theme of our machine is Charlie and the Chocolate Factory. So far, we have only built a few parts for it, but hopefully we'll get a lot done after break!

This has been a fun experience because I have had a chance to use all the physics I have learned and apply it in real life! While not much of the machine is built yet, what we've done has shown me that while the concepts I've learned have been helpful, the really complicated ideas don't always work out how you expect them to. For instance, one of the parts I was in charge of building was a lever, and when a car fell onto the lever, it lifted another lever up, which causes a pipe wrapped up in a "red carpet" to fall and trigger a mouse trap. You can see this in action in the video below! We had some difficulty making this, especially with finding the right weights to put on the levers and where (knowing about torque has finally come in handy!). We used a fair amount of trial-and-error, because not only did the lever have to stay horizontal before the car landed on it, it needed to lift the other lever just enough to make the pipe fall down. It took a few hours, but when we got it to work we knew it would be a great addition to the machine.

While we still have a ways to go, we have a lot of cool new ideas to try out! It seems that the coolest ideas are usually the trickiest to get to work, but I'm sure if we're creative enough we'll find a way.

Thoughts on iFoundry

So now that the semester is nearly over, I have a better realization of what the purpose of iFoundry is. Also, keeping in mind this is a pilot course, there are some aspects of iFoundry that I don't think were necessary, and some things I would add to the course.

For me, the iFoundry course has served as a better introduction into engineering than the standard ENG 100 course. I knew people in that class who gave presentations introducing themselves and stuff like that, but weren't properly introduced into their major at U of I. In that regard, I think ENG 198 did a great job. We had ELA's who gave presentations on various topics we would inevitably encounter at some point during college, and projects where we got a taste of what engineers actually do.

There are some things that I felt should be different, however. The first is timing. Now it would obviously be difficult for anyone to be able to predict how many weeks of classes it would take to build the projects we built, but we were definitely pressed for time on both projects. The first one was extended, which then cut into our time to work on the second one. The good news about project 2 was that we could work on it outside of class pretty easily, but there were issues that many groups had with getting parts they ordered in time for the next week's class. Now, my proposition to fix this is to make the ENG 198 course 2 hours long and 1 day a week. When we only had an hour to work on our project, we would waste valuable time getting out our materials and putting them away at the beginning and end of class, but having one class that is twice as long would eliminate this problem.

As for the lectures, I'm not so sure how much I actually learned from them. A lot of it was common sense (take initiative, be ethical, etc), and I honestly had hoped for information I couldn't have figured out on my own. For instance, a great lecture would be one on the things that engineers wish they had known going into college. Knowing what was coming in college would prepare us better for what was ahead. Regardless of what the lectures were about, time could be made for them by having this weekly schedule: lab, lab, lecture, lab lab, lecture, etc. This would give less lecture time and more lab time than the current course, but I think it's appropriate since I feel we learned a lot more from the labs than we did from the lectures. Also, having more time to work on labs would allow us to actually devote time to improving and optimizing our projects instead of simply getting them to work.

Overall, I am glad I took ENG 198 as opposed to ENG 100. I really do feel we learned more about Engineering at U of I, and the projects were pretty cool to work on. Most of the hiccups we ran into were simply because it is the first time this was done at U of I, and I think that over time the problems will get smoothed out.

First Mechanical Engineering Project

In my ME 170 class, we have been learning how to use the ProEngineer Wildfire software. This is basically a CAD program that allows you to make a 3-D model and engineering drawings for any part or assembly of parts you want. Most of the time, we have a lab that accompanies each week of lectures where we learn about all the different functions we can use to make our parts, but a few weeks ago we were tasked with making a creative part of our choice, which would then be rapid prototyped on the 3-D printer in the Mechanical Engineering Lab. This was really an individual project, but one of my friends is in my lab section, and we decided to make two individual parts that could then be connected to each other to make one bigger part. We decided on making a replica of the Ark of the Covenant (the biblical box containing the original stone tablets of the 10 commandments and other holy relics). Now, since the location and even the very existence of such an object is arguable, we decided to use the interpretation of what it looks like in Indiana Jones: Raiders of the Lost Ark. I think we did a pretty good job...

Here's the Ark from the movie

This is the Ark that we made

To make the Ark, I used ProE to design the lid, while my friend designed the box it sits on. All in all, this took over 10 hours (each) for us to do. Obviously, the more complicated the design, the more time it takes to make, but there were a lot of aspects to this that were more complicated than we thought. For instance, this is not an assembly in which pieces must fit together and have a specific function. Rather, it is more of an artistic piece. The only thing we really had to collaborate on was the general design and making sure the lid fit on the box properly. Beyond that, we each pretty much did what we wanted. But, like I said, this is an artistic design, and ProE is more of a technical software. That meant that we had to make something look aesthetically pleasing, and then assign numbers and dimensions to it so it could be represented using the geometry from the software.

The base of the lid wasn't too difficult. I made a solid box and cut out quarter cylinders along the top and bottom edges, giving it the tapering edge. The hard part was then putting the angels on top. To make the angels, I actually started with the wings first. This was where I initially drew what I thought it should look like, then altered the dimensions of each line, arc, circle, and fillet so it was represented by a number (remember this software needs specific geometry, or strong dimensions, to work properly). Next, I put the two wings on either side of where I figured the angels should go, and made another shape that looked as close to a kneeling person as I could (this was especially difficult to do using only lines, arcs, circles and fillets). When both parts were finished, the files were sent to the lab where they use a process called stereolithography to make a prototype of our design. We just got the parts back the other day, and we're pretty happy with how it turned out! Overall, I think our final product was pretty close to what we had envisioned. We were definitely ambitious with this project, but I'm glad we worked as hard as we did on it because it paid off.

Our current (and final) project is one with at least 12 parts, with at least one moving relative to the other. Once again, we've chosen a pretty difficult design, but I'll post more about that later.

Engineering, Mythbusters style

With sites like Hulu making it easier than ever to watch TV online, I've spent a fair amount of time in between classes catching up on shows I've missed on my computer rather than my TV. I've also started watching some shows I may not have watched had it not been as easy as searching for it online. One of these shows is Mythbusters. I used to watch the show a little, but only if it was on when I was looking for something to watch. Now, I've kind of become an addict, and I'm only worried for when I run out of episodes.

What I've noticed is that Mythbusters is really all about engineering. It's not engineering in the traditional sense, but a lot of the show revolves around problem solving, ingenuity, and (very) creative thinking. Mythbusters is as much about science as it is about engineering. Sure, they conduct a lot of experiments, but in order to set up most of these experiments they usually have to build something that's never been built before, or at least build upon their knowledge of the subject at hand to find a way to test the sometimes crazy myths.

I've already seen some things on the show that I can relate to at school. In one episode, they were testing the myth that a skydiver with a faulty parachute landed on a see saw, rocketing a small girl up 7 stories and landing her safely on the top of a building. The first innovation the Mythbusters made was to use a heavier mass falling from a shorter distance that would impart the same force as a grown man falling at terminal velocity. When the weight fell on the see saw, the myth was busted when the see saw was completely destroyed, launching the girl only a few feet instead of the desired 7 stories. Adam and Jamie recognized that the energy from the falling "skydiver" was being used to bend the metal see saw, and not being transferred to the girl as kinetic energy. They solved this problem by building a heavy-duty see saw. First, they modeled the see saw on a computer program which allowed them to artificially test the strength to see whether or not it could withstand such a large impact. This reminded me of ProE Wildfire, which, as a mechanical engineer, I have been using to model parts and assemblies that can then be sent to manufacturers. After their design was shown to work, they made a V-shaped see saw. Each end of the V was connected to the other using a high tension nylon rope with a very high breaking strength. When the skydiver landed on this see saw, the energy would not be absorbed by the nearly indestructible see saw, but rather transferred to the girl who ended up flying 13 stories into the air. Even though this see saw does not exist in real life, and the chances of this happening are extremely improbable, they proved the concept that, given the proper conditions, the myth is true.

What I learned from this myth and from watching the show is that sometimes you have to think beyond what you already know to be truly innovative. The see saw needed for this myth simply did not exist, so they thought outside of the box and came up with one they knew would work. They took one of the most simple machines, the lever and fulcrum, and improved it to the point where it was strong enough to withstand the impact of a grown man falling at terminal velocity, and transfer energy efficiently. That sort of ingenuity, coupled with an impressive knowledge of the scientific and physical world, can lead to some really remarkable ideas.

I feel that Mythbusters tries to hide the fact that they are an engineering show. They rarely use the term "engineering," and while most of the hosts actually worked in special effects for movies, they clearly demonstrate they are extremely skilled engineers. While it is evident that not much of what they do is practical in the real world, the processes they use and the thought they put into their designs are very applicable to the field of engineering.

more on our steam car...

So, it's been awhile since we actually did the steam car competition, but I figured I should give an update on how it went.

It started out kind of rough. We over-fueled the car for the first test (fastest start - whose car could make three revolutions of the turbine the fastest), which literally put our project up in flames. This wasn't a huge problem, but the rubber band drive shaft melted, and we lost that contest. We simply replaced the rubber band and we were good to go for the speed test. There were two brackets for this, and we were first in all but one race during the first bracket. For the second bracket, we were up against a team that had done equally well in their respective bracket, but we ended up being faster (which was a pretty big surprise to us). Here's a video of us winning the last race.

In addition to winning the actual race, we also came in first for the "Meanest" car (thanks to the intimidating wings we added at our last meeting), and we also placed in the competition for best design.

I think a lot of this competition was luck, because we simply didn't have enough time to properly test how we could modify our car to make it consistently faster or start up quicker. The fastest start competition was almost entirely luck, as it primarily depended on how much water you had in the boiler, and the subsequent ratio of how quickly that water could come to a boil and the vapor pressure the steam could create. All in all though, I think the fact that everyone's cars worked as well as they did proved we were successful with our projects. I'm really looking forward to the next project, as we'll have enough time to test our Arduino and make sure it works as smoothly as possible.

Steam Car

So after several weeks of assembling our steam car, it is almost time to put it to the test. We finally got the car to run last week, and it seems like it holds up pretty well. As for speed, it looks like we're right on track with the rest of the class (which is not saying much), but I'm pretty happy with our first engineering endeavor.